Just ordered one from the USA. Should know when it arrives; there is a backlog of 1-2 months.
Informal reviews from the USA suggest that the mach1 will be better than any non-ANR headset (which it is, believe it or not) and as good as the majority of ANR headsets.
Anything which goes right inside the ear has the potential to be very very good, on every front.
One can also fit specialised custom-made earplugs to this. There are outlets in the USA doing these.
ANR is also very easy to implement and would be much more effective, due to the very small cavity that's left.